Siemens 6ES5497-4UB42 Simatic S5 PLC CPU Module

Siemens 6ES5497-4UB42 is a double-wide front connector for the SIMATIC S5 family, designed to mate with the 497 front interface and accept 20-pin screw-terminal wiring. The module occupies two slots in a backplane, providing the front-end connection between S5 CPUs and field wiring. Specifically described as a front connector for SIMATIC S5 systems, it is associated with S5-135U and S5-155U CPU modules, making it a critical accessory for legacy automation racks that rely on screw-terminal I/O connections. Cataloged by Siemens and distributors as the 6ES5497-4UB42 front connector, this part enables reliable front-end wiring for I/O signals in older S5 installations. Applications include retrofitting or maintaining legacy SIMATIC S5 controllers where a robust front-end connection via 20-pin terminal blocks is required, interfacing a compatible S5 CPU with the appropriate screw-terminal assemblies. This front connector, rather than a CPU, plays a key role in enabling continued operation of aging S5 hardware within plants that require durable, screw-terminal field wiring.